The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 2000
Filed:
Sep. 14, 1998
Masashi Mizuno, Osaka, JP;
Masuo Tada, Osaka, JP;
Norio Yamazaki, Osaka, JP;
Toshiaki Ohmori, Tokyo, JP;
Taiyo Toyo Sanso Co., Ltd., Osaka, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Super clean air suitable for use in a tunnel-type wafer transport system, etc., is produced efficiently with the specific energy consumption reduced and the yield improved by making good use of part of cooling energy and gas produced in a low temperature separation type nitrogen producing apparatus. Material air 1a collected from the atmosphere is pretreated in a room temperature adsorption tower 7, this pretreated air is adsorption treated at -60.degree. C. in a first low temperature adsorption tower 9, and the treated air 1c is further adsorption treated at -150.degree. C. in a second low temperature adsorption tower 10, thereby producing super clean air 1e containing not higher than 1 ppb of the chemical components other than nitrogen, oxygen and noble gases and having a dew point of not higher than -100.degree. C. The airs 1b and 1c are cooled in heat exchangers 12, 13 and 14 by utilizing cooling energy produced in the low temperature separation type nitrogen producing apparatus, that is, the low temperature gas 3f passed through an expansion turbine 38 from a rectifying tower 37.